Printing telegraph apparatus



April 25, 1950 w. J. zx-:NNER

PRINTING TELEGRAPH APPARATUS 13 Sheets-Sheet l Filed April 22, 1948 INVENTOR WALTER J. ZENNER BYZw-L? ATTORNEY W. J. ZENNER PRINTING TELEGRAPH APPARATUS April 25, 1950v Filed April 22, 1948 13 Sheets-Sheet 2 INVENTOR WALTER J. ZENNER avg f ATTORNEY W. J. ZENNER PRINTING TELEGRAPH APPARATUS April 25, 1950 Filed April 22. 1948 15 Sheets-Sheet 3 INVENTOR WALTER J. ZENNER egim M ATTORNEY April 25, 1950 w. J. zENNl-:R

PRINTING TELEGRAPH APPARATUS 15 sheets-sheet 4 Filed April 22. 1948 mvENToR WALTER J. ZENNER BY? @W i ATTORNEY April 25, 1950 w. J. zENNER 2,505,729

PRINTING TELEGRAPH APPARATUS Filed April 22, 1948 13 She'ets-Sheet 5 FIG. I3 499 ,93 C FIG. |4

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19| u/lss las g l l mvENToR WALTER J. ZENNER ATTORNEY April 25, 1950 w. J. ZENNER PRINTING TELEGRAPH APPARATUS 13 Sheets-Sheet I6 Filed April 22, 194s Hill-wry? Ln!! AAJ FIG.I9

INVENTOR April 25,Y 1950 w. J. zENNER PRINTING TELEGRAPH APPARATUS April 25, 1950 w. J. zENNER PRINTING TELEGRAPH APPARATUS 13 Sheets-Sheet 8 Filed April 22, 1948 hun WALTE R J. ZE NNER /EZV'WW ATTORNEY Vl B pril 25, 1950 w. J. zENNER PRINTING TELEGRAPH APPARATUS 13 Sheets-Sheet 9 Filed April 22, 1948 mm .wm

INVENTOR WALTER J. ZENNER mg @uw ATTORNEY April 25, 1950 w. J. zENNER 2,505,729

PRINTING TELEGRAPH APPARATUS Filed April 22, 1948 13 Sheets-Sheet l0 INVENTOR WALTER J. ZENNER 5.27 WAM ATTORNEY April 25, 1950 w. J. zENNER 2,505,729

PRINTING TELEGRAPH APPARATUS Filed April 22, 1948 13 Sheets-Sheet 11 FIG. 42

INVENTOH WALTER J. ZENNER WZL? ATTORNEY April 25 1950 w. J. zENNER 2,505,729

PRINTING TELEGRAPH APPARATUS Filed April 22, 1948 13 Sheets-Sheet l2 FIG. 45 FIG. 44

INVENTOR WALTER J. ZENNER ATTORNEY April 25, 1950 w. J. ZENNER PRINTING TELEGPAPH APPARATUS 13 Svheets-Sheet 13 Filed April 22, 1948 FIG. 47

FIG. 50

INVENTQR WALTER J. ZENNER ATTORNEY Patented Apr. 25, 1950 2,505,729 PRINTING TELEGRAPH APPARATUS Walter J. Zenner, Des Plaines, Ill., asslgnor to Teletype Corporation, Chicago, Ill., a corporation of Delaware Application April 22, 1948, Serial No. 22,653

i Claims.

This invention pertains to printing telegraph apparatus and more particularly to telegraph printers of the page type.

The principal object of the present invention is to provide a printing telegraph apparatus with mechanical refinements of parts to enhance the smoothness and rapidity of operation thereof.

Another object of the invention is the provision in a telegraph printer of novel driving mechanisms therefor resulting in an apparatus capable of exceptionally high speed operation.

A further object of the invention is to provide a page recorder which is exceedingly rapid in 'operation and very smooth and quiet in performance due to the fact that the rapid movements of the principal parts are provided with controlled acceleration and deceleration to render the mechanism devoid of shocks.

According to the present invention there is provided a novel selecting mechanism of the type disclosed in U. S. Patent No. 2,339,313 issued to W. J. Zenner, but of considerably improved construction and arrangement throughout, of decreased weight and of increased compactness and emciency, thereby increasing the speed of operation.

Specifically, the telegraph printer according to the present invention comprises a stationary platen, having a type carrier of novel design movable with respect therewith. The type box or carrier slidably supports therein a group of type pallets, the positioning of the type pallet in registry with the printing point being achieved coordinately. The type carrier comprises a rectangularly shaped box having aligned slots or openings in opposite faces thereof to provide dual bearings for the slidable type pallets. Compression springs encircling said pallets within said box hold the pallets in retracted position so that upon receiving a printing stroke from the print hammer, the pallet is actuated to compress its spring and the type face is brought into contact with the record medium.

According to the embodiment of the invention disclosed herein, the type carrier is divided horizontally into four sections, each having four rvertical rows of characters. Identifying said sections from left to right as i, 2, 3, and 4; sections l and 2 contain lower case or unshift characters, and sections 3 and 4 contain upper case or shift characters. Thus, the center line between sections I and 2 is indicative of the normal position of the type carrier in the unshift or lower case position, so that the type carrier is actuated rightwardly and leftwardly from this center line for the selection of lower case characters. Similarly, the center line between sections 3 and 4 is indicative of the normal position of the type carrier in the shift or upper case position, so that the type carrier is actuated rightwardly and leftwardly from this center line for the selection of upper case characters.

The characters are arranged on the type box or carrier for selection in response to the receipt of code signals in such a manner that characters represented by signals having a marking characteristic for a predetermined impulse (the third impulse) of the five unit code, are on sections l and 3 of the type carrier, and characters represented by signals having a spacing characteristic for the said predetermined impulse are on segments 2 and 4 of the type carrier. Signal responsive means is provided which upon` the receipt of said predetermined impulse "will bias the segment to move in one direction or the other from either of said center lines depending upon the character of said predetermined impulse received. Thus, if the type carrier is in the unshift or lower case position whereat printing from sections i and 2 is effected, the reception of a marking characteristic for said predetermined impulse (which in the embodiment disclosed herein is the third interval position of the five unit code) will cause printing to be effected from section l, and conversely, the reception of a spacing characteristic for said predetermined impulse will cause printing to be effected from section 2. Moreover, if the type carrier is in the shift or upper case position whereat printing is effected from sections 3 and 4, the reception of a marking characteristic for said predetermined impulse will cause printing to be effected from section 3, and the reception of a spacing characteristic for said predetermined impulse will cause printing to be effected from section 4.

The apparatus described generally hereinbefore will, for a five unit code, provide thirty-two selections.- However, since there are sixty four possible selective positions on the type carrier, the type carrier may be moved the distance between one of the aforesaid center lines to the other by a case shifting and unshifting mechanism similar in ultimate effect to the case shifting mechanism of the usual form of printing telegraph apparatus. This case shifting mechanism comprises apparatus for shifting the entire type box or carrier from the position to printl from sections i and 2 to the position to print from sections 3 and 4, or vice versa upon receipt of a shift or unshift signal.

Signal responsive means is also provided for permutatively shifting a series of three stop members for controlling the distance the type box or carrier will move when biased in one direction or the other of the center line. The impulses received in two of the impulse periods (for example, the fourth and fifth intervals of the five unit code) will control the setting of these stops, whereas the impulses received in the other two impulse periods (for example, the iirst and second intervals of the five unit code) will control the height to which the type carrier is elevated. The type characters on the type carrier are arranged in four horizontal rows. Periodically operated mechanisms are provided for urging the type box or carrier to move rightwardly or leftwardly or to move upwardly at predetermined times in the cycle of operation of the apparatus and said permutatively set means is accordingly provided for interrupting the coordinate movements of the type box or carrier at various right and left positions and different levels.

The foregoing brief description of the features of the present' invention apply particularly to the mode of selecting the type to be utilized in printing a character. In accordance with the embodiment of the invention disclosed herein, the type box or carrier is attached to a steel band which is adapted to be wound around a pair of drums disposed one at each end of the printer. The print hammer unit is also attached to a separate steel band which is also adapted to be wound around said pair of drums. The drum disposed at the left end or beginning of line posi tion houses a carriage return spring which is operated according to an old and well known principle. The print hammer assembly or unit operates in a step-by-step manner to impart regular and uniform spacing movement to the print hammer under the control of a pawl and ratchet spacing mechanism, and the idler pulleys around which the steel band is directed are mounted on fixed pivots. On the other hand, the type carrier assembly likewise operates in a uniform step-by-step manner, but the idler pulleys around which the steel band is directed are mounted on a parallelogram device to facilitate variable horizontal shifting movement of the type carrier independently of the uniform character spacing movement to eifect type selection. The print hammer is of the firing pin type.

In the embodiment of the invention described` herein, it is necessary to perform additional functions such as line feed, carriage return and ribbon feed. The line feed mechanism embodied inthe printing apparatus according to the invention differs from the conventional pawl and ratchet line feed mechanism by substituting a gear for the ratchet and a pair of specially-designed racks for the usual pawl linkage. The gear is fixed to the platen so as to berotatable therewith. The

The ribbon y printing. A feature of the invention resides in the provision of clutches individual to the various function mechanisms. such as the type carrier positioning clutch, line feed clutch, function clutch, spacing clutch, code bar actuating clutch and selector clutch.

A more complete understanding of the invention may be had by reference to the following description when considered in conjunction with the accompanying drawings, wherein,

Fig. 1 is a perspective view of the printing apparatus according to the present invention;

Fig. 2 is a front elevational view of the apparatus shown in Fig. 1, parts being broken away to show more clearly the operating elements of the apparatus;

Fig. 3 is a sectional view taken on line 3--3 of Fig. 2;

Fig. 4 is a sectional View taken on line I-I of Fig. 2;

Fig. 5 is a sectional view taken substantially on line 5-5 of Fig. 2;

Fig. 6 is a fragmental front elevational view of the apparatus showing the type carrier shift mechanism according to the invention;

Fig. 7 is a sectional view taken on line 1--1 of Fig. 6;

Fig. 8 is a perspective representation of the signal responsive code bar selector arrangement;

Fig. 9 is a View of the orientation mechanism;

Fig. 10 is a fragmentary perspective view of a portion of the selector mechanism;

Fig. 11 is a view to illustrate more clearly certain elements shown in Fig. 10;

Fig. 12 is a fragmentary perspective view of the shift and unshift function control devices in the selector arrangement;

Fig. 13 is a left side elevational view of the printer;

Fig. 14 is a fragmentary front elevational view showing the relationship of certain of the parts illustrated in Fig. 13;

Fig. 15 is a cross-sectional view showing the function operating mechanism;

Fig. 16 is a top view of portion I6-I 6 of Fig. l5; Fig. 17 is a fragmentary view showing the elevator detent mechanism;

Fig. 18 is a right side elevational view of the printer;

Fig. 19 is a fragmentary front elevational view showing the relationship of certain of the parts illustrated in Fig. 19;

Fig. 20 is a sectional view taken on line 20-20 of Fig. 13;

Fig. 21 is a front elevational view of the print hammer assembly;

Fig. 22 is a side elevational view of the print hammer assembly and associated parts of the printer;

Fig. 23 is a detail view of the print hammer;

Figs. 241.028, inclusive, are detail views of the character spacing mechanism;

Fig. 29 is a sectional view in elevation showing the several clutch devices;

Fig. 30 is a diagrammatic representation of the clutch operating levers;

Figs. 31 and 32 are detail views of the line feed clutch;

Fig. 33 is a perspective representation of the line feed mechanism;

Fig. 34 is a fragmentary detail view of the line feed operating means;

Figs. 35`to 43, inclusive, are detail views of the inking ribbon mechanism;

Fig. 44 is a front elevational view of the type carrier according to the present invention;

Fig. 45 is a side elevational view of the type carrier;

Fig. 46 is a top view of the type carrier. and

Figs. 47 to 50 are views illustrating a modified form of character spacing mechanism.

Having reference to Fig. 1 of the drawings, the numeral II designates the base portion of the printer framework upon which the apparatus is suitably mounted. In this embodiment of the invention the apparatus is shown as a receiving instrument, and no transmitting apparatus has been shown in connection therewith. It will be understood, however, that suitable transmitting apparatus to which the apparatus of the present invention may respondmay be and usually is supplied wth an apparatus for receiving messages such as that to be described herein. A suitable transmitting and controlling apparatus is shown in U. S. Patent No. 1,595,472 issued to H. L. Krurn. August 10, 1926.

The selector assembly is designated by the reference numeral I2 and comprises a selector magnet i3 (Figs. ,l and 8) suitably supported on a bracket (not shown) attached to the side frame of the printer apparatus. The selector mechanism I2 is essentially of the type shown and described in U. S. Patent No. 2,339,313 issued January l8,-1944, to W. J. Zenner. Extending from the printer side frame` is an armature mounting bracket I5 .(Fig. 8) which carries, through the instrumentality of `a hinge I 6, an armature pivot plate Il. tTo one end of the armature pivot plate il is fastened one end of a spring ld, the other end of which is attached to an adjusting screw I9 (Fig. l) carried in a bracket 2l appropriately mounted on the side frame. The function of spring It is to bias the armature pivot plate I l counterclockwise (as viewed in Fig. 8) about the hinge I B in response to a spacing condition impressed on the selector magnet i3. In

i response to a marking signal condition the magnet i3 becomes energized and armature l'I is attracted toward the pole piece 22, thereby stretching the spring l2. The armature plate I1 thus oscillates in response to received code combinations of marking and spacing impulses.

Cooperating with the leitward extremity (as viewed in Fig. 8) of armature plate Il' are a plurality (ve in the present embodiment) of selector levers 23 pivotally mounted on a pivot shaft 24. Each of the selector levers 23 is provided with a cam follower projection `25 and is adapted to cooperate with a selector cam 2li individual thereto. Cams 26 are fixed to a shaft 2l to which rotation is imparted by means of a motor 28 (Fig. 1) Selector levers 23 are normally biased toward cams 2li by individual springs 29 in such a manner that the projection 25 normally bears against the outer periphery or dwell portion of the cam 26 and in this position the upper extremity of each lever 23 cooperates with the edge of the armature plate il. Associated with each lever 23 and operably disposed thereabove is an interponent 3I pivotally mounted on a pivot shaft 32 suitably journaled in the printer frame. Interponents 3i are normally biased in a clockwise direction (as viewed in Fig.

GTI

a) by their individual springs ai so that the ex- Cooperatively related to interponents 3l are a corresponding series of substantially T-shaped members 34. The rounded extremity of the horizontal arm of the member 34 cooperates with interponent 3I and normally bears thereagainst under the influence of individual springs 35. The upwardly directed arm of each member 34 is pivotally articulated to the horizontal arm of an associated bell crank lever 35 pivotally mounted on a shaft 31. The vertical arm of bell vcrank lever 36 is likewise pivotally articulated to associated code bars 62 to l0. Cooperating with said code bars are a plurality of selectable bars 39 for controlling the various functions of the apparatus, as will be hereinafter described.

The depending arm of each T-shaped member 34 is provided with shoulders 4I and 42 which are adapted to coact selectively with a pair of reciprocably operating bail members 43 and 44, respectively. Bail member 43 is provided with stepped shoulders 45 to correspond to the echelon arrangement of members 34 and the horizontal arms of bell cranks 3E, which shoulders 45 cooperate with the shoulders 4I. Similarly, bail member 44 is also provided with stepped shoulders 46 to coact with the shoulders 42..

Bail members 43 and 44 are mounted for vertical sliding movement on frame portion 4l, and each is provided at its lower end with openended slots 48 `and 49, respectively, adapted to receive the circularly conformed ends 5I and 52 of an oscillating drive member 53| fixed to a shaft 54 appropriately journaled in the frame of the apparatus. At the opposite end of shaft 54! (as shown in Fig. 10) is xed an arm 55, and juxtapositioned to arm 55 and freely mounted on shaft 54 is an arm 56. Fixedly carried on arm 56 is a stud 5l which is adapted to bear against a shoulder 58 on arm 55 due to the pull of a spring 59 which is stretched 'between the extremities of the arms 55 and 55. Also connected pivotally to arm 56 through the medium of stud 5l is an eccentric link 6I cooperatively related to an eccentric 5I] fixed on the main operating shaft 2l of the printer apparatus.

Associated with the armature lever I'I is a clutch trip lever 'III (Figs. 8, 9 and 29) which is pivotally supported on a pivot stud I2 and is normally biased clockwise by a spring 'I3 against the edge of the armature Il. A plurality of cams including the selector cams 26 are mounted on the operating shaft 2l on which is also mounted a clutch mechanism III represented in Fig. 9 by its stop lever 14. The clutch mechanism thus indicated III is of the type disclosed in copending application Serial No. 707,176 filed November l, 1946. by A. N. Nilson et al., and lever 'I4 is analogous to lever 21 of said application.

A bell crank lever l5 is pivotally mounted at pivot 'I6 on an orientation plate I'I of well known construction; for example, comparable to the plate 'I5 shown in Fig. 9 of U. S. Patent No. 1,989,710 issued to A. H. Reiber et al. The rotation of plate 'I1 is eiected through the instrumentality of rack and pinion means, exemplied by thumb screw 80 in Fig. 29, and is similar to that shown in Fig. 9 of said copending Nilson et al. application. Arm 'I8 of the bell crank lever 151s adapted to cooperate with the clutch y lever 14, and the other arm 'I9 of said lever 'I5 is provided at its extremity with a pair of studs 8l and 82 suitably spaced to guide the lever 'II so that as the lever 1I is actuated by the spring 13, this actuation would be imparted through the studs 8| and 82 to the bell crank lever 15, as will hereinafter appear. The contour of the lever 1| adjacent the studs 8| and 82 is such that the vertical position of the lever 1| will not be disturbed when the orientation adjustment of plate 11 is being made. A cam 83 is secured to the shaft 21 in a position to cooperate with the stud 82 of bell crank lever 15. Cam 83 in its stop or rest position presents the notched portion thereof to the stud 82 as shown in Fig. 9.

Referring to Figs. 8 to 11, a description of the operation of the mechanism so far described will now be given. The selector cam assembly carried on shaft 21 is rotated at a speed substantially equivalent to the speed of code. pulsing, and operating in conjunction therewith is theselectormagnet I3 which may be connected either directly or indirectly to the signal line (not shown). In accordance with well known practice, the normal stop condition of the line is marking, hence the selector magnet |3 is normally energized and its armature |1 is held attracted to present the end thereof into the path ofthe trip lever 1|. During the first line impulse or start interval which is of spacing nature, the selector magnet I3 is de-energized and the spring I8 retracts the armature |1 to the dotted position 84 as shown in Fig. 9 to permit spring 13 to rotate the lever 1| clockwise, which, through studs 8| and 82 rotates bell crank lever 15 similarly to disengage the end of arm 18 from the clutch lever 14. This action is permitted because the notch 85 of cam 83 is opposite stud 82. The clutch exemplied by lever 14, thereupon is permitted to rotate to, in turn, impart rotation to the selector cam assembly. At the termination of the start interval, the cam 83 upon rotation will act to cam the bell crank lever counterclockwise to hold the end of arm 18 in the path of clutch lever 14. Studs 8| and 82 will also hold the lever 1| free of the armature |1 thereby imposing no load upon said armature. Lever 1|, therefore, cannot respond to the pull of spring 13 until the notch 85 is again presented in register with stud 82.

During the ensuing rotation of the selector cam assembly, the selector cams 28 will control the selection of levers 23. Each of the levers 23 (five in the present embodiment) is provided with a cam follower projection 25, as previously described, which cooperates with the periphery of its associated cam 26. The cams 26 are of similar cam contour but are displaced on the shaft 21 angularly so that the cam projections thereon are disposed in a helically arranged series whereby coaction with the cam followers will occur in a sequential manner as the series of cams 28 rotates in synchronism with the speed of code impulsing.

As the selector cams 28 rotate, the notch or depression 88 of the rst cam 26 is presented to the cam follower projection 25 during the first signal impulse of the received code combination. If said impulse is of marking nature the armature I1 Will assume its attracted position and the rst lever 23 will be free to respond to the pull of its spring 29. Lever 23 will then be withdrawn from beneath the end of slide or interponent 3| which under the influence of its spring 33 will rotate slightly to rest upon the flange 81 of reset bail 88 pivotally mounted at pivots 89 on frame member 8|. As the selector cam 28 continues to rotate, the high portion 92 thereof will coact with the ycam projection 25 to rotate lever 23 in a counterclockwise direction, whereupon the slide or interponent 3| will be urged leftwardly to cause T-member 34 to rotate slightly about pivotal interconnection 83 to bring shoulder 4| of member 34 beneath the bail blade 45 which on its downward movement will draw member 34 downwardly to in turn impart counterclockwise rotation to bell crank lever 38 to cause the associated code bar 82 to be shifted leftwardly (as viewed in Fig. 8).

If the first significant code impulse had been a spacing impulse, the magnet I3 would have been de-energized, and the armature |1 would have been released to block the clockwise movement of lever 23 (Fig. 9) as previously described, whereupon the extremity of interponent 3| will continue to ride on top of lever 23 and no leftward slidable movement of interponent 3| will occur. T-member 34 will remain in the position shown in Fig. 8, so that the shoulder 42 thereof will be presented in the path of the reciprocating bail 44 to cause upward movement of member 34 to in turn rotate bell crank 38 clockwise to impart rightward movement to code bar 82.

A locking lever 84 is normally spring biased f toward the armature |1 to retain the armature in its released or attracted position during the signal impulse interval. The function and operation of this lever is fully disclosed in U. S. Patent No. 1,783,382 granted toH. L. Krum. Following the selective operation of the selector levers 23, as previously described, the reset bail 88 is operated by its cam 85 to raise the interponents, which have previously been dropped, to restore the interponents to the position shown in Fig. 8.

The code bars 82 to 10 extend across the printer and control the selection of functions, such as line feed, carriage return, shift and unshift, and also the selection of type characters for printing, as will lbe hereinafter described. As shown in Fig. 22, the code bars 82 to 10 are suitably supported for movement in the direction of their length by brackets 20 and 30 secured to plate 253.

Having reference to Fig. 29, a driving pinion |0| secured to the shaft |02 driven by the motor 28, serves to transmit power through a gear |03 to the main operating shaft 21 of the printer. On shaft 21 are carried a plurality of clutches for governing the various functions of the apparatus. The clutch indicated generally as |05 controls the power for elevating the type box or type carrier 99 (Figs. 1 and 44). Clutch |08 controls the power for operating the line feed mechanism. Clutch |01 is the function lever clutch, and acts, as will hereinafter appear, to. control a function lever bail 381 (Fig. 15). Clutch |08 is the spacing clutch and controls the power for operating the stepping of the printing mechanism. Clutch |09 is the code bar operating clutchv and controls the oscillation of drive member 53, shown in Figs. 8 and 10. The clutch indicated generally as controls the power for operating the selector cams.

Clutches |05 to |09 are of the construction illustrated in Figs. 31 and 32. The particular clutch shown is clutch |08 of Fig. 29 which controls the line feed mechanism. Having reference to Figs. 31 and 32, a ratchet wheel ||2 constantly rotates with the constantly rotating shaft 21 and constitutes the driving portion of the clutch. The driven portion comprises a pair of pawls I I3 and |4 pivotally mounted on a flange ||5 of a sleeve member ||8 loosely carried on the shaft 21. Pawls ||3 and ||4 are normally biased clockwise by individual springs ||1 distended between the end of the pawls and associated spring posts ||3 mounted on the flange H51 One pawl, or even three or more pawls may, of course, be used. Integral with the sleeve ||8 is flange 9 provided with diametrically disposed studs |2| `and |22 carrying rollers |23 and |24 which cooperate with an accelerator lever |20, as will presently be described. The clutch |06 is shown in Fig. 32 in its sto condition of operation with the .stop portion |26 of flange H bearing against the extremity of its associated stop gate |21, shown more clearly in Fig. 15. However, just prior to the engagement of stop lug or portion |26 with stop gate |21, during a cycle of rotation of the clutch, the pawls ||3 and 4 have become disengaged from the ratchet wheel 2 due to the coaction of the tail portion of each pawl with its associated defiector |29 which is a fixed part of the machine.

Rollers |23 and |24 are adapted to cooperate with accelerator arm |29 pivoted on a lstud |3| fixed to a bracket |32 suitably carried on a pair of cross bars |33 (one of which is shown in Fig. 29). An accelerator spring |34 normally biases arm |29 in a counterclockwise direction (as viewed in Fig. 32) against one or the other oi' the rollers |23 or "I 24 (depending upon the position of the clutch) to tend to rotate the sleeve ||6 clockwise (as viewed in Fig. 32) which clockwise rotation is prevented by the portion |26 bearing against the gate |21.

`When the extremity of gate |21 is removed from the path of portion |26 (in a manner hereinafter described), the driven portion of the clutch is released for rotation. pawls |3 and ||4 are prevented by deectors |28 from engaging the ratchet ||2 at this time. This is done purposely in order to prevent a clashing of the rapidly moving ratchet teeth with the quiescent pawl teeth. Thus the function of the accelerator |29 becomes apparent. As soon as the stop gate |21 is disengaged from portion |26, the accelerator arm |29, due to the energy stored in spring |30, suddenly imparts clockwise rotation to sleeve ||6 to in turn impart a rapid forward movement to pawls ||3 and Hi. Thus, pawls |13 and are thrown free of the fixed deiiector members |28 and are brought into engagement with the ratchet wheel H2 by their associated springs In this manner, momentum is imparted to the pawls ||3 and ||4 before their engagement is effected with the rapidly rotating ratchet wheel i i2, thereby preventing the breaking of the ratchet teeth or the pawl teeth. As the clutch driven member or sleeve ||6 is completing its rotation, energy is again stored in the accelerator spring |34 by the coaction of rollers |23 or |24 with the cam surface |35 of the accelerator arm |29. Then, as the sleeve I6 completes its rotation, the tail portions of the pawls ||3 and |14 again cooperate with the fixed deiector members |29 to effect the disengagement of the pawls ||3 and ||4 from the ratchet ||2.

Clutches |05, |01, |08, and |09 are of similar construction to clutch |06. However, these various clutches are initiated into rotation under the control of the mechanism schematically shown in Fig. 30. Having reference to Fig. 29, the armature |1, in response to a spacing signal, releases lever 1|, which, through studs 8 |82, coacts with arm 19 of release lever 15 to rotate said lever to release arm 10 from clutch to thereby initiate rotation of the selector cam assembly |36. The selector cam assembly includes a cam However, the y suitably shaped to actuate, at a predetermined" time in the rotation of the assembly, a trip lever |31 fixed to a. shaft |33 suitably supported in the apparatus. To the other end of shaft |38 is fixed a stop gate |39 (similar to stop gate |21) which coacts with a stop portion in clutch assembly |09 which is similar to portion |26 in clutch |06. Associated with clutch assembly |09 is a cam which cooperates with a trip lever |4| fixed to a shaft |42 lappropriately mounted in the apparatus. Also fixed to shaft |42 are/"stop gates |43 and |44, for initiating operation ci clutches |01 and |05, respectively, since in the embodiment of the invention shown the clutches |05 and |01 are operated substantially simultaneously. Included in the clutch assembly |05 is a trip-od.' cam which operates a trip lever |45 fixed to a shaft |46 to the other end oi which is fixed a gate |41 for initiating operation of the clutch |08.

Thus, in the cycle of operations the selector cam assembly |36 (Fig. 29) is initiated into rotation upon the receipt of the start impulse, and at a predetermined time in its rotation a cam |49 thereon actuates the lever |31 to rock the shaft |38 to thereby operate stop gate |39 to initiate therotation of clutch |09 to effect the operation of the code bars and function levers. A cam |5| in the clutch assembly |09 in turn actuates the arm |4| at a predetermined time to rock the shaft |42 to operate the stop gate |44 to initiate the rotation of the clutch |05 to effect the operation of the type box 99. A cam |52 in the clutch assembly |05 actuates, at a predetermined time, the lever arm |45 to rock the shaft |46 to operate the stop gate |41 to initiate operation of the spacing clutch |03. The selector cam assembly |36 is also provided with the cam 83 which cooperates with the U-shaped lever 15, for

the purpose aforesaid.

Having reference to Figs. 1, 2, 6, and 44 to 46, I

the type carrier 99 comprises a hollow box-like structure having aligned apertures in the front and rear faces thereof into which are slidably supported the type elements |55. A coiled com- 4pression spring |56 having one end secured to the shank of the type element encircles each type element |55 and functions to hold the type element in the retracted position (as shown in Fig. 46). The type carrier 99 is provided with flanges |51 through the medium of which the carrier 99 is mounted on a traveling carriage |58 by means of screws |59. In the present embodiment, the carriage |58 is provided with a pair of upper rollers |6| and a lower roller |62 adapted to ride on the upper and lower edges of a track member |63 (Figs. 6 and 13). I

Track |63 is secured near each end by means of bolts |64 to the upper ends |60 of correspondingly conformed members |65 and |66 (Figs. 13 and 18, respectively). Members |65 and |66 are corresponding elements of corresponding parallel motion arrangements located on each side or end of the apparatus-as shown in Figs. 13 and 18. Referring to Fig. 13, the member |65 is pivotally Varticulated at pivot |61 to the free end of a lever arm |68 pivotaliy mounted on a stud |619 fixed to the side plate |1| of the apparatus. The lower end of member |65 is pivotaliy connected through pivot |12 to the free end of a lever arm |13 pivotaliy connected at |14 to the side frame |1i. Lever |13 is provided at its extremity with a projection |10 adapted to slide vertically in a guideway |80. Movement vertically is imparted to the members |65 and |66 in the following manner. The clutch |05 is indicated in broken. lines in ll Fig. 13, but at the predetermined time in the cycle of operations of the apparatus, the gate |44 (Fig. 30) therefore is actuated t0 release the clutch |06 for a full revolution, the clutch being provided with only one pawl ||4.

Associated with the clutch |05 is a disc |14 which is provided eccentrically thereon with a stud to which is pivotally connected one end of a link |16, the other end of which is connected pivotally to the end of a lever arm |11 fixed to a rock shaft |18 suitably journaled in the apparatus. Also fixed to shaft |18 is an arm |19 to the free end of which is pivotally connected the lower end of a vertical link |8|. The upper end of link |8| is pivotally connected to a lever arm |82 which is pivotally supported at |83 to the side frame or plate |1|. A connecting link |84 is connected pivotally at |85 to the lever arm |82. The upper end of link |84 is pivotally connected to arm |81 of the lever |68 which is pivotally supported at |69 on the Side plate |1|. Arm |81 is provided with a depending projection |88 to the extremity of which is pivotally articulated one end of a link |9|, the other end of which is pivotally connected to a ribbon spool platformr |92 rockably mounted on the side plate |1| by means of pivot stud |93. Fastened to side plate |1| is a guide comb |94 which is suitably slotted for guiding the movement of levers |13 and |82.

A link |95 comprising one element of a toggle or knee-action device is pivotally connected at |96 to the extremity of lever arm |82. The other element of the toggle comprises the link |91 which is pivotally connected at |98 to the member |65 and at |90 to the other element or link |95. The toggle or knee-action device illustrated is of the type disclosed in co-pending application Serial No. 656,284 iiled March 22, 1946, by W. J. Zenner. Toggle element |91 is provided with an antieipator or buffer portion |99 adapted to cooperate with a selected one of the selectable code bars 63, 65, 61, and 10. Toggle element |91 is normally urged in a counterclockwise direction by a spring distended between a spring post on the element |91 and a spring post o`rr the member |65. Toggle element |91 is also provided with a projection 202 which cooperates with a lateral projection 203 of member |65 to limit the counterclockwise movement or rotation of the toggle element |91 by the spring 20|. Thus, the toggle device is shown in Fig. 13 in its quiescent condition with the projection 202 resting against the stop 203. f

The structure just described in Fig. 13 is employed for governing the vertical selective movement of the type box 99. In Fig. 18 is shown a corresponding structure which in conjunction with the structure shown in Fig. 13 serves to raise the track |63 to in turn raise the type box 99. Thus, having reference to Fig. 18, an arm 204 is xed to the shaft |18, and a link 205 connects the arm 204 to a lever 206 corresponding to lever |82. Lever 206 is connected by a link 201 to a lever 208 corresponding to the lever |68. Lever 298 is connected at its free end to the upper end of member |66, while the lower end of member |66 is connected to a lever 209 similar to lever |13. Levers 208 and 209 are connected to the member |66 in a parallel-motion manner, identical with the manner in which levers |68 and |13 are connected to the member |65.

A toggle or knee-action device comprising elements 2|| and 2|2, and spring 2|3 is` also pro-v vided btween lever 206 and member |66. Elements 2|| and 2`|2 are pivotally articulated at 2| 0. Element 2|! is provided with an anticipator portion 2|4 which also cooperates with the stop bars 63, 65, 61 and 10, and together with the corresponding structure shown in Fig. 13 an arrangement is thus provided for elevating the track |63. Element 2|2 is also provided with a projection 2|5 which cooperates with a lateral projection 2|6 on member |66. Lever 208, through projection 2 1, operates a link 2|8 which, in turn, actuates a ribbon spool platform or support 2|9 corresponding to support |92.

.In the operation of the type box elevating mechanism shown in Figs. 13 and 18, the bars 63, 65, and 61 are selectively projected into the path of anticipators |99 and 2|4 and stop shoulders or abutments 22| and 222 of members |66 and |66, respectively, through the instrumentality of the selector arrangement shown in Fig. 8. For example, in response to a marking condition the member 34 (Fig. 8) will be actuated to its leftward position to place its shoulder, 4| in the path of the bail 43 to thereby rotate bell crank 36 counterclockwise, thus moving bar 63 or 65 leftwardly (as viewed in Fig. 8, or rightwardly as viewed in Fig. 20). There are bell cranks 36 associated with bars 63 and 65 and not with bar 61. Of course, there are bell cranks 36 associated also with bars 62, 64 and 66 for a purpose to be hereinafter described.

As clearly shown in Fig. 18, bar 61 is provided with a vertically directed arm 223 adapted to cooperate with a shoulder 224 (Fig. 20) on 4bar 63 and a corresponding shoulder on bar 65. Bar 61 is normally spring-biased rightwardly by a spring 229, as viewed in Fig. 20, so that it is permitted to move to the right only upon the selective operation rightwardly (as viewed in Fig. 20) of both bars 63 and 65. Having reference to Fig. 6 it will be noted that the type carrier 99 is provided with four horizontal rows of type faces, and to effect printing in said rows, the type carrier 99 is elevated to any one of said four positions. These positions are governed by the stop bars 63, 65, 61, and 10. The bar 10 is i'lxed in its position and determines the highest position to which the carrier 99 is moved, whereat printing will be effected from row 225. When printing is to be effected from row 226 the bar 63 is selected and is actuated rightwardly (as viewed in Fig. 20) to limit the upward movement of anticipators |91 and 2|4, and shoulders 22| and 222. Under this condition of operation the bar 61 is held against movement by the shoulder 224 on bar 65, and on the other hand, when the bar 65 is selectively actuated rightwardly to position the carrier 99 for printing from row 221, the shoulder 224 on bar 63 will hold bar 61 against movement. However, when printing is desired from row 228, vboth bars 63 and 65 are selectively actuated rightwardly, thereby removing the block from proiection or arm 223 to permit bar 61 to move rightwardly. When neither bar 63 nor bar 65 is selected, then the anticipators are permitted to abut bar 10 to effect printing from row 225, as indicated above.

The selection of bars 63, 65 and 61, through the instrumentality oi' the selector cam assembly |36 and the code bar operating mechanism shown in Fig. 10, causes a cam associated with the code bar operating mechanism to operate an arm |4| (as previously described) to rock the shaft |42 (Fig. 3'0) which through arm |44 will initiate the rotation of the type carrier clutch |05. As viewed in Fig. 13, the clutch |05 governs the rotation of the disc |14 which. in turn, through link |16, con- 13 trols the oscillation of arm |11 to rock the shaft |18 on which are fixed the arm |19 (Fig. 13) and the arm 204 (Fig. 18)

Arms |19 and 204 actuate their respective links |8| and 205 to operate their respective lever arms |82 and 206 to control the operation of their respective knee-action mechanisms. Since the free ends of levers |82 and 206 are connected to the lower extremities of their respective knee-action mechanisms, and stop members |65 and |66 are connected to the upper extremities thereof, the elevation of the members |65 and l 66, and therefore the track |63, is accomplished through the knee-action mechanisms until a stop bar 63, 65, 61, or has been encountered, whereupon the knee-action joints bend at their pivots |90 and 2|0, as described in the afore-mentioned copending application, Serial No. 656,284.

As set forth in said copending application, the buffer portions or anticipators |99 and 2|4, in their upward movement are the ist to strike a stop bar 63, 65, 61, or 10 which has been projected into their path of movement, and in response to further movement imparted to levers |82 and 206 by the shaft |18 through links |8| and 205, respectively, the knee-action elements |91 and 2|2, due to the knee-action, tend to rotate about pivots |98 and 200, thereby stretching` their respective springs 20| and 2|3, until the striking edges of the anticipators |99 and 2 i4 and of the stop shoulders 22| and 222 coincide, and said shoulders 22| and 222 thus are brought to bear against the selected stop bar. Thus, said knee-action elements provide a yielding or cushioning means for the movable members |65 and |66.

It is observed that the movement imparted to 61, and 10. The utility of the knee-action drive resides in the provision of a compensating means for these two different types of movement. Furthermore, the shock due to the moving object or members |65 and 66 striking against the fixed stops 63, 65, 61 or 10 is dissipated, and as the members |65 and |66 approach the stops 63, 65, 61, or 10A at high speed, the impingement of stop proiections or shoulders 22| and 222 upon the stop bars 63, 65, 61, or 10 is anticipated by the anticipator or buier portions |99 and 2 I4, so that a gradual slowing down of the movement of members |65 and |66 occurs. whereby the members |65 and |66 are caused to come torest lightly against the selected stop bars 63, 65, 61, or 10. Moreover, as the stop projections 22| and 222 recede from the stnn here. the movements thereof are. likewise governed by the knee-action means, whereby the acceleration of motion of members |65 and |66 corresponds inversely to the deceleration, so that the members |65 and |66 start from rest and gradually accelerate until the motion of link 205 (or |82) is attained.

Also pivotally connected to the extremity of lever |62 is a detent or check member 23| provided with a guiding proiection 232 adapted to cooperate with a guide comb 233. As the member 23| is raised by lever |82, a cam portion 234 (Fig. 17) of projection 232 cooperates with a cam surface 235 on a guide member 236 to direct a check pawl tooth 231 into one of the notches 238 on member |65. A dei-ent member 24|, corresponding to member 23|, is also pivotally connected to lever 206 Fig. 18) and is provided with a projection or extension 242 having a cam por tion cooperating with a, guide 243 to cam a pawl tooth 244 into engagement with one of the .notches 245 in the member |66. The vertical movement oi' member 23| is always the same, while the vertical movement of member varies according to the stop member 63, 65, 61, or 10 selected. Accordingly, the pawl tooth 231 will be cammed forward at the same point, but since the movement of member |65 varies, the pawl 231 will engage the notch 238 in register therewith as determined by the stop bars. Corresponding cooperation will result between pawl 244 and notches 2415 (Fig. 18).

The mechanism for elevating the type box to any one of four horizontal rows has now been described. However, to bring the type pallets in these horizontal rows into registry with the printing point, the following described mechanism is employed. Having reference to Figs. 8 and 15, it was disclosed that code bars 63, 65, and 61 determined the elevation of the type box or carrier 99 to control printing from the diierent horizontal rows 225, 226, 221, or 228. The code bars 62, 64, and 66, however, determine the degree of horizontal movement of the type carrier to complete the selection of a particular type face in a particular row. Referring to Fig. 8, the code bars 62, 64, and 66 are also actuated rightwa'rdly or leftwardly by their associated bell cranks 36 in the same manneras previously described :in connection with code bars 63 and 65. As shown in Fig. 3, the code bars 62 and 64 are notched at 246 to receive the ends of one arm of small bell crank levers 248 and 249 pivotally mounted on a pivot 25| carried in a bracket 252 secured to the front plate 253 of the printer. The extremities of the other arms of the bell cranks 248 and 249 engage notches in slidable stop elements 254 and 255, respectively, appropriately mounted on a bracket 251 secured to plate 253.

Interposed between stop elements 254 and 255 and controlled thereby is a third slidable stop element 256. As viewed in Fig. 3, stop element 256 is normally biased rearwardly by a spring 258 stretched between said stop element and the plate 253. Stop elements 254, 255 and 256 are each provided with a pair of oppositely directed stop proiections 259 and 26|. The nroiections 259 and 26| of each stop element diier in length from the corresponding projections of the other two stop elements in such a manner that the type carrier 99, as will presently appear, will be brought into registry with the different vertical rows of type pallets |55 depending upon which of the stop elements 254, 255, and/or 256 have been actuated.

Cooperating with the stop projections 259 and 26| is a buffer member 262 provided with buffer portions 263 interposed between the stop projections 259 and 26| and associated knee-action mechanisms of the type disclosed in the aforementioned copending application Serial No. 656,- 284. Buffer member 262 is slidably mounted on a plate 264 bv means of slot and screw mounting means 265.

When spacing impulses are received in the fourth and iifth intervals of the code, the code bars 62 and 64 remain in the positions shown in Fig. 3, and accordinglv, the projections 259 and buier portion 263 will be in alignment as shown, whereby the longest proiections, which are on the middle stop element 256, are effective. When a marking impulse is received in the fourth interval and a spacing impulse is received in the fifth interval, only code bar 62 will be actuated 

